1. Field of the Invention
The invention relates to a cooling device for the drive of an elevator.
2. Discussion of the Prior Art
Elevator systems which operate a lifting piston using hydraulic fluid generate considerable amounts of heat which are produced by the internal friction of the hydraulic fluid. Cooling devices are necessary to cool the hydraulic fluid.
Japanese reference JP 55115601 discloses a cooling device for the oil of a hydraulic elevator. A fan, which is used when the oil temperature rises, is arranged between the car lifting mechanism and the oil reservoir, on the side of the oil line.
This solution has the disadvantage that, in order to cool the oil, an additional device is used in the machine room, which additional device requires energy and space. In addition, the cooling takes place at a distance from the lifting mechanism. This brings about a situation in which the oil temperature in the lifting mechanism can rise in an uncontrolled way. In addition, the fan is used exclusively for cooling the drive means.
Accordingly, it is an object of the present invention to provide a cooling device that has the advantage that it is space-saving. At the same time, it is ensured that the drive means is cooled in a simple and low cost manner, directly at the lifting device.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in a cooling device for drive means of a lifting device which drives a car of an elevator, which cooling device comprises a ventilation apparatus for cooling the drive means. The ventilation apparatus is arranged on the car so as to ventilate at least part of the lifting device.
In one embodiment of the invention, the ventilation apparatus is arranged on the car in such a way that it ventilates the interior of the car. This has the advantage that the interior of the car and the lifting device are ventilated simultaneously with a single ventilation apparatus, which gives rise to an energy-saving cooling system.
It is particularly advantageous to have means for conducting the air from the ventilation apparatus to the lifting device to be present inside or outside the car. In this way, the air is conducted to the correct point, without unnecessary losses.
A further advantage is that the means for conducting the air are embodied as a hollow air duct, preferably made of sheet metal, which is connected at one end to an outlet of the ventilation apparatus and at the other end surrounds the lifting device at least partially. These can be manufactured very inexpensively.
It is also advantageous for the lifting device for driving the elevator to be arranged in a depression which extends along one outer side of the car and which also serves as an air duct for the lifting device. Spaces in the elevator system which are already present are therefore used as air ducts. The costs can thus be reduced further.
It is also advantageous for the ventilation apparatus to be a fan, permitting a commercially available device to be used.
In order to reduce costs even further, it is particularly advantageous for the ventilation apparatus to be embodied as a component of a cooling system or to interact with a central cooling system of a building. There is therefore no need for a separate ventilation apparatus.
All the features mentioned can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the invention.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.